In a shielded gate trench MOSFET, as compared to a typical MOSFET, the shield electrode may reduce the gate-drain capacitance and increase the cut-off voltage of the transistor. The gate electrode and the shield electrode may be insulated from each other by an inter-electrode dielectric (IED). The IED may have sufficient mass and thickness to support the potential difference between the shield electrode and the gate electrode. In addition, the interface well charge and dielectric well charge at the interface between the shield electrode and the IED layer and in the IED layer are primarily related to formation of the IED layer.